index.html

http://pinterest.com/pin/create/button/?url=http://www.domain.com&description=&media=

ex:

http://pinterest.com/pin/create/button/?url=http://www.youworkforthem.com&media=http://www.youworkforthem.com/img/eps/E1174/E1174_00.jpg&description=Escapism 30 pulls further away from reality by manipulating organic materials into beautiful, hi-res bursting textures. This is art, this is space, this is nature, this is chaos. Use as you wish.

pinterest.loader.js

(function() {
  window.PinIt = window.PinIt || { loaded:false };
  if (window.PinIt.loaded){ return; }
  window.PinIt.loaded = true;
  function async_load(){
    var s = document.createElement("script");
    s.type = "text/javascript";
    s.async = true;
    if (window.location.protocol == "https:") {
      s.src = "https://assets.pinterest.com/js/pinit.js";
    } else {
      s.src = "http://assets.pinterest.com/js/pinit.js";
      var x = document.getElementsByTagName("script")[0];
      x.parentNode.insertBefore(s, x);
    }
  }
  if (window.attachEvent) {
    window.attachEvent("onload", async_load);
  } else {
    window.addEventListener("load", async_load, false);
  }
})();

pinterest.pinit.js

(function () {
  var links = document.getElementsByTagName("a");
  var pin_links = [];
  for (var k=0, total=links.length; b<total; k++){
    pin_links.push(links[k]);
  }
  for (var i=0; pin_links.length > 0; i++) {
    var link = pin_links.pop();
    if (!link.className || link.className.indexOf("pin-it-button") < 0) {
      continue;
    }
    var link_href = link.getAttribute("href");
    var params = {};
    // parse querystring into an object
    link_href = link_href.slice(link_href.indexOf("?") + 1).split("&");
    for (var k=0, total=link_href.length; k<total; k++) {
      var key_val = link_href[k].split("=");
      params[key_val[0]] = key_val[1];
    }
    params.layout = link.getAttribute("count-layout");
    params.count = link.getAttribute("always-show-count");
    var qs = "?";
    var url = window.location.protocol + "//d3io1k5o0zdpqr.cloudfront.net/pinit.html";
    for (var f in params) {
      if (params[f]) { // hasOwnProperty ?
        url += qs + f + "=" + params[f];
        qs = "&"
      }
    }
    var frame_el = document.createDocumentFragment("iframe");
    frame_el.setAttribute("scrolling", "no");
    frame_el.allowTransparency = true;
    frame_el.frameBorder = 0;
    frame_el.style.border = "none";
    if (params.layout == "none") {
      frame_el.style.width = "43px";
      frame_el.style.height = "20px"
    } else if (params.layout == "vertical") {
      frame_el.style.width = "43px";
      frame_el.style.height = "58px"
    } else {
      frame_el.style.width = "90px";
      frame_el.style.height = "20px"
    }
    link.parentNode.replaceChild(frame_el, link);

    // track the iframe in google analytics
    // http://code.google.com/apis/analytics/docs/tracking/gaTrackingSite.html#trackingIFrames
    _gaq.push(function() {
      var pageTracker = _gat._getTrackerByName();
      frame_el.setAttribute("src", url);
      frame_el.src = pageTracker._getLinkerUrl(url);
    });
  }
}());